Star photography with an old Russian lens

Just for fun, I tried some astrophotography with an old (1976) Soviet-era Russian lens.  The lens is the Industar-50-2, (ИНДУСТАР-50-2) an M42 screw-mount 50mm f/3.5 lens.  This lens is remarkably tiny, only 68 g (2.4 oz).  It is a 4-element 3-group Tessar design.

This lens was designed to cover the standard 35-mm film format (what is now called "full frame" with respect to digital cameras).  Some initial test shots with a Sony A7iii camera showed very strong corner distortions at f/3.5, so I instead switched to a smaller-sensor E-M5iii camera and shot at f/4.  Even so, star smearing is still evident in the corners of the frame. 

Here is an image of the lens mounted on the E-M5iii with an M42 adapter:

 The following images were obtained on Tuesday night under a bright waxing gibbous moon, so exposures were limited to 30 sec.  Measurements of star separations show that the lens has an actual focal length of 52.7 mm.  This is consistent with many so-called "50mm" lenses from the film era, which were often closer to 52mm as revealed in lab tests publshed by Modern Photography and Popular Photography magazines.

I used a Kase AstroBlast diffusion filter held in front of the lens.  The lens has a non-standard 35.5-mm filter thread, which is incompatible with my screw-in filters. 

 

Saturn rising over Snowshoe Mountain

Constellation Lyra.  Vega is the bright star.

part of Cassiopeia

The Little Dipper barely fits in the frame.  Polaris is near the right edge.

The Andromeda Galaxy (M31) near center. 

Pleiades rising

 These two images are from Oct 04 and 05, before a run of rainy weather.  The Pleiades star cluster, also known as Messier 45 (M45) was rising over Snowshoe Mountain in the early evening.  Red and green airglow adds color to the otherwise dark sky.

04 Oct. equipment: Sony A7iii + Rokinon AF 85mm f/1.4 II lens

05 Oct. Sony A7iii + Rokinon 75mm f/1.8 + Hoya Softon filter

Morning Milky Way and Zodiacal Light

 At 5 am on Friday morning the sky was clear and calm.  The sky brightness to the east was measured as 21.45 mpsas, which is pretty good.  Jupiter is rising in the east and Orion is already high in the southeast.

Zodiacal Light and the winter Milky Way over Snowshoe Mountain

 This image was taken with an Olympus 8mm f/1.8 fisheye lens.  On the left, Jupiter is embedded in the triangular glow of Zodiacal light, which continues to arc upward from left to right.  On the right, the winter Milky Way arcs upward from right to left past Sirius and Orion.  The ridge line of Snowshoe Mountain is silhouetted against green and red airglow.

 This vertical fisheye image extends up past the zenith and into the northwest sky, just catching the eastern end of Cassiopeia.

 This image was obtained with a Laowa 7.5mm f/2 rectilinear lens and a Hoya Sparkle-6 filter.

The Moon fades, the Milky Way reappears

 After several days of deluge the sky was clear on Thursday night and last night.  There is now a window of darkness between the end of astronomical twilight and the rising of the waning Harvest Moon.

The last-quarter Harvest Moon was captured sinking behind the trees on the Bristol Head ridgeline yesterday afternoon:

 Later that evening (Friday) the Milky Way was once again an impressive sight:

 This photo was obtained with an OM-5II camera and an Olympus 8mm f/1.8 fisheye lens.  A digital low-pass filter was applied in post processing to suppress the faint stars.  This is a fisheye lens, so the view extends from the southern horizon up past the zenith and into the northern sky.

The next two images are also fisheye views with similar processing. 

view to the northwest

 

view to the north east

Three objects of interest are circled in the image above.  The planet Saturn is visible on the right.  In the middle, the galaxies M31 (Andromeda Galaxy, top) and M33 (Triangulum Galaxy, lower) are circled.  The Andromeda Galaxy is easily visible to the unaided eye with a dark sky like last night.  At a distance of 2.5 Million light years (Mly), it is the farthest easily seen object with the naked eye.  The Triangulum Galaxy is slightly farther away at a distance fo 2.8 Mly.  At magnitude 5.8, it is theoretically visible to the unaided eye under extremely dark conditions.  I tried, but my aging eyes could not pick it out last night.  The sky was nicely dark at the end of the observing session, with a measured sqml value of 21.62 mpsas in the eastern sky.

Harvest Moon ascending

 The weather gods were either distracted or being benevolent on Saturday night.  Clouds covered the western sky, but the view to the east stayed clear long enough to catch the rising Harvest Moon.

All pictures were with a 60mm f/6 refractor.

Anticipation....

 

There it is...

Through the trees

Harvest Moon, 99.7% full

Harvest Moon preview

The full Harvest Moon occurs today (Saturday) at 10:50 am MDT, but the prospects for viewing at moonrise this evening currently do not look good.  Last night there was a break in the clouds that allowed a preview as the Moon cleared the Snowshoe Mountain ridgeline at 7:45 pm.

These images were obtained with an Apertura 60mmED f/6 telescope.

 

25 September, 99.6% full

Autumnal Equinox

The Autumnal Equinox, when the Sun crosses the celestial equator in the southward direction,  marks the end of summer and the beginning of autumn.   This year it occurred on Tuesday, 22 September. 

Here are two pictures taken on the day before the equinox (summer), and the day after (autumn).

On the road to Love Lake.  Monday.

 

Snow on the La Garitas. Wednesday morning